Methods for Liberating Trichome Fibers from Portions of a Host Plant

ABSTRACT

Improved processes for liberating trichome fibers from non-seed portions of a trichome-bearing host plant are provided, as well as inventive fibrous structures comprising trichome fibers.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of, and claims priority under 35U.S.C. § 120 to, U.S. patent application Ser. No. 16/388,986, filed onApr. 19, 2019, which is a continuation of U.S. patent application Ser.No. 15/378,430, filed on Dec. 14, 2016, now U.S. Pat. No. 10,309,057,granted Jun. 4, 2019, which claims the benefit, under 35 USC § 119(e),of U.S. Provisional Patent Application Ser. No. 62/269,430, filed onDec. 18, 2015, the entire disclosures of which are fully incorporated byreference herein.

FIELD OF THE INVENTION

The present invention relates to methods for liberating trichome fibersand to fibrous structures comprising individualized trichome fibers.

BACKGROUND OF THE INVENTION

Historically, fibrous structures including those that are used to makesanitary tissue products have been made with softwood fibers andhardwood fibers. For example, softwood fibers have typically made upgreater than 20% by weight on a dry fiber basis of through-air-driedfibrous structures. The softwood fibers are longer fibers than thehardwood fibers and they provide greater strength properties to thefibrous structures than do the hardwood fibers. However, softwood fiberstypically do not provide the level of softness benefit provided byhardwood fibers.

Trichome fibers have been identified as a good substitute for softwoodfibers to provide softness while contributing sufficient strength to afibrous structure in which they are incorporated. Trichomes areepidermal attachments of a varying shape, structure and/or function of anon-seed portion of a plant. In one example, a trichome is an outgrowthof the epidermis of a non-seed portion of a plant. The outgrowth mayextend from an epidermal cell. In one embodiment, the outgrowth is atrichome fiber. The outgrowth may be a hairlike or bristlelike outgrowthfrom the epidermis of a plant. Trichomes may protect the plant tissuespresent on a plant. Trichomes may for example protect leaves and stemsfrom attack by other organisms, particularly insects or other foraginganimals and/or they may regulate light and/or temperature and/ormoisture. They may also produce glands in the forms of scales, differentpapills and, in roots, often they may function to absorb water and/ormoisture.

Individualized trichome fibers can be artificially separated fromportions of their host plant. U.S. Pat. No. 7,811,613 describes aprocess for liberating trichome fibers that includes a milling operationof non-seed portions of a trichome-bearing plant followed by a screeningor air classifying step to separate the trichome fibers from otherportions (such as the leaves and stems) of the host plant. FIGS. 1 and 2illustrate such a process. A feedstock of material that includes leaves,stems, and attached trichome fibers is fed into a vacuum system 10 thathas two outlets, an upper outlet 12 to collect dust, and a lower outlet14 to collect further processable material 16. The main purpose ofvacuum system 10 is to transport the feedstock and to begin cleaning thefeedstock of dirt, dust, and other waste material. Material 16 continueson to a cyclone 18 that also contains an upper outlet 20 for collectingdust, and a lower outlet 22 that feeds a hammermill 24. Magnets 26 and28 are included to remove any metal that has been introduced into thefeedstock via harvesting, transportation, or handling equipment.Hammermill 24 breaks the leaves and stems up into smaller pieces andseparates at least some of the trichome fibers from leaves and stems.Material 30 coming out of hammermill 24 is then directly or indirectlyrouted into a series of air classifiers 32 and 34, as can be seen inFIG. 2. Air Classifier 32 has a waste outlet 33 for collecting the smallleaf and stem pieces. Separated trichome fibers are routed to airclassifier 34 and then collected for making fibrous structures.

Unfortunately, systems such as those described above produce low yields(mass of feedstock divided by the mass of trichome fibers collected fromair classifier 34); for example, up to around 15%. Low yields discouragecommercial leveraging of alternative, sustainable resources for fibersthat can be used in paper products. One of the reasons for the low yieldis that while trichome fibers can be separated from leaves and stems viathe hammermill, many of the separated fibers are still tangled with orotherwise associated with the small leaf and stem pieces. Theseassociated trichome fibers then flow out of the waste outlet 33 andnever make their way into the fiber collection used for making fibrousstructures. The inventors of the present invention have discovered thatone or more additional steps of disassociating separated fibers fromother plant portions significantly increases trichome fiber yield. Theone or more disassociation steps have also been found to remove dirt andother foreign materials to a greater level so that the collectedtrichome fiber masses are lighter in color and comprise fewer darkspecks, making fibrous structures comprising the processed trichomefibers more consumer acceptable.

BRIEF DESCRIPTION OF THE DRAWINGS

The following detailed description of specific embodiments of thepresent invention can be best understood when read in conjunction withthe drawings enclosed herewith.

FIG. 1 is a schematic of an exemplary prior art milling process.

FIG. 2 is a schematic of a prior art process as described in U.S. Pat.No. 7,811,613.

FIG. 3 is a schematic of illustrative process steps according to thepresent invention.

FIG. 4 is a light micrograph of a leaf and leaf stem illustratingtrichome fibers present on red clover, Trifolium pratense L.

FIG. 5 is a light micrograph of a lower stem illustrating trichomefibers present on red clover, Trifolium pratense L.

FIG. 6 is a light micrograph of a leaf illustrating trichome fiberspresent on dusty miller, Centaurea gymnocarpa.

FIG. 7 is a light micrograph of individualized trichome fibersindividualized from a leaf of dusty miller, Centaurea gymnocarpa.

FIG. 8 is a light micrograph of a basal leaf illustrating trichomefibers present on silver sage, Salvia argentiae.

FIG. 9 is a light micrograph of a bloom-stalk leaf illustrating trichomefibers present in silver sage, Salvia argentiae.

FIG. 10 is a light micrograph of a mature leaf illustrating trichomefibers present on common mullein, Verbascum Thapsus.

FIG. 11 is a light micrograph of a juvenile leaf illustrating trichomefibers present on common mullein, Verbascum Thapsus.

FIG. 12 is a light micrograph of a perpendicular view of a leafillustrating trichome fibers present on wooly betony, Stachys byzantine.

FIG. 13 is a light micrograph of a cross-sectional view of a leafillustrating trichome fibers present on wooly betony, Stachys byzantine.

FIG. 14 is a light micrograph of individualized trichome fibers in theform of a plurality of trichome fibers bound by their individualattachment to a common remnant of a host plant, wooly betony, Stachysbyzantina.

The embodiments set forth in the drawings are illustrative in nature andnot intended to be limiting of the invention defined by the claims.Moreover, individual features of the drawings and invention will be morefully apparent and understood in view of the detailed description.

DETAILED DESCRIPTION OF THE INVENTION

The following text sets forth a broad description of numerous differentembodiments of the present invention. The description is to be construedas exemplary only and does not describe every possible embodiment sincedescribing every possible embodiment would be impractical, if notimpossible. And it will be understood that any feature, characteristic,component, composition, ingredient, product, step or methodologydescribed herein can be deleted, combined with or substituted for, inwhole or part, any other feature, characteristic, component,composition, ingredient, product, step or methodology described herein.Numerous alternative embodiments could be implemented, using eithercurrent technology or technology developed after the filing date of thispatent, which would still fall within the scope of the claims. Allpublications and patents cited herein are incorporated herein byreference.

It should also be understood that, unless a term is expressly defined inthis specification using the sentence “As used herein, the term ‘______’is hereby defined to mean . . . ” or a similar sentence, there is nointent to limit the meaning of that term, either expressly or byimplication, beyond its plain or ordinary meaning, and such term shouldnot be interpreted to be limited in scope based on any statement made inany section of this patent (other than the language of the claims). Noterm is intended to be essential to the present invention unless sostated. To the extent that any term recited in the claims at the end ofthis patent is referred to in this patent in a manner consistent with asingle meaning, that is done for sake of clarity only so as to notconfuse the reader, and it is not intended that such a claim term belimited, by implication or otherwise, to that single meaning. Finally,unless a claim element is defined by reciting the word “means” and afunction without the recital of any structure, it is not intended thatthe scope of any claim element be interpreted based on the applicationof 35 U.S.C. § 112, sixth paragraph.

The term “individualized trichome fibers” as used herein means trichomefibers which have been artificially separated by a suitable method forindividualizing trichome fibers from their host plant. In other words,individualized trichome fibers as used herein means that the trichomefibers become separated from a non-seed portion of a host plant by somenon-naturally occurring action. In one example, individualized trichomefibers are artificially separated in a location that is sheltered fromnature. Primarily, individualized trichome fibers will be fragments orentire trichome fibers with essentially no remnant of the host plantattached. However, individualized trichome fibers can also comprise aminor fraction of trichome fibers retaining a portion of the host plantstill attached, as well as a minor fraction of trichome fibers in theform of a plurality of trichome fibers bound by their individualattachment to a common remnant of the host plant. Individualizedtrichome fibers may comprise a portion of a pulp or mass furthercomprising other materials, including non-trichome-bearing fragments ofthe host plant.

Individualized trichomes may be converted into chemical derivativesincluding but not limited to cellulose derivatives, for example,regenerated cellulose such as rayon; cellulose ethers such as methylcellulose, carboxymethyl cellulose, and hydroxyethyl cellulose;cellulose esters such as cellulose acetate and cellulose butyrate; andnitrocellulose. Individualized trichomes may also be used in theirphysical form, usually fibrous, and herein referred to “trichomefibers”, as a component of fibrous structures.

Trichome fibers are different from seed hair fibers in that they are notattached to seed portions of a plant. For example, trichome fibers,unlike seed hair fibers, are not attached to a seed or a seed podepidermis. Cotton, kapok, milkweed, and coconut coir are non-limitingexamples of seed hair fibers.

Further, trichome fibers are different from nonwood bast and/or corefibers in that they are not attached to the bast, also known as phloem,or the core, also known as xylem portions of a nonwood dicotyledonousplant stem. Non-limiting examples of plants which have been used toyield nonwood bast fibers and/or nonwood core fibers include kenaf,jute, flax, ramie and hemp.

Further trichome fibers are different from monocotyledonous plantderived fibers such as those derived from cereal straws (wheat, rye,barley, oat, etc.), stalks (corn, cotton, sorghum, Hesperaloe funifera,etc.), canes (bamboo, bagasse, etc.), grasses (esparto, lemon, sabai,switchgrass, etc.), since such monocotyledonous plant derived fibers arenot attached to an epidermis of a plant.

Further, trichome fibers are different from leaf fibers in that they donot originate from within the leaf structure. Sisal and abaca aresometimes liberated as leaf fibers.

Finally, trichome fibers are different from wood pulp fibers since woodpulp fibers are not outgrowths from the epidermis of a plant; namely, atree. Wood pulp fibers rather originate from the secondary xylem portionof the tree stem.

“Fiber” as used herein means an elongate physical structure having anapparent length greatly exceeding its apparent diameter, i.e. a lengthto diameter ratio of at least about 10. Fibers having a non-circularcross-section and/or tubular shape are common; the “diameter” in thiscase may be considered to be the diameter of a circle havingcross-sectional area equal to the cross-sectional area of the fiber.More specifically, as used herein, “fiber” refers to fibrousstructure-making fibers. The present invention contemplates the use of avariety of fibrous structure-making fibers, such as, for example,natural fibers, such as trichome fibers and/or wood pulp fibers, orsynthetic fibers, or any other suitable fibers, and any combinationthereof.

The present invention is directed to improved processes for liberatingtrichome fibers from non-seed portions of a trichome-bearing host plant.Exemplary process steps are shown in FIG. 3. A feedstock 100 comprisingmilled leaves, stems, still attached trichome fibers, and separatedtrichome fibers is provided; e.g., via a process such as shown in FIG. 1and described above. Various milling apparatuses can be used to breakthe leaves and stems into small pieces and to separate at least some ofthe trichome fibers. Nonlimiting examples of such devices include a ballmill, a pin mill, a hammermill, a rotary knife cutter such as a “WileyMill” and/or a “CoMil” sold by Quadro Engineering of Waterloo, Ontario,Canada.

Feedstock 100 is fed into a screw conveyor 101 to feed a venturimechanism 102. A blower 104 communicates pressurized fluid 105 toventuri mechanism 102. Pressurized fluid 105 becomes entrained with themilled feedstock 100 and is directed to a fluid flow resistor in theform of a breaker plate 106. In one example, the entrained pressurizedfluid with the feedstock 100 is directed against the breaker plate 106.Forces encountered because of the venturi mechanism 102 and impactingthe breaker plate 106 disassociate at least some of the separatedtrichome fibers from the leaf and stem pieces to create a refinedfeedstock 110. Other approaches beyond a breaker plate can be employedto help disassociate separated trichome fibers from remaining plantportions. The fluid flow of the pressurized fluid entrained with themilled feedstock can be impeded, interrupted, or altered by variousmechanisms, including, for example, in-line mixers, bends and otherdirectional changes in the fluid flow conduits to introduce increasedfrictional losses in the fluid flow, impellers, in-line screens, and thelike. Different types of forces can also be employed, including impactforces and shear forces, for example.

Milled feedstock 100 can alternatively be processed through otherapparatuses prior to being communicated to air classifiers. Suchapparatuses include, but are not limited to, refiners, beaters,additional millers (dry and wet), homogenizers, pulpers, cotton millers(also called “pickers” and “openers”), separators, carders, anddeflakers.

Trichome fibers can be sorted and collected through various techniquesof processing refined feedstock 110. As exemplified in FIG. 3, refinedfeedstock 110 is communicated to a first air classifier 112. Screeningequipment and air classifying equipment are well known in the art. Asuitable air classifier is the Hosokawa Alpine 50ATP, sold by HosokawaMicron Powder Systems of Summit, N.J. Other suitable classifiers areavailable from the Minox Siebtechnik.

A portion of refined feedstock 110 exits air classifier 112 as a wastestream 114. While a target of waste stream 114 are the milled stems,milled leaves, and dirt, inevitably some of the separated trichomefibers and still attached trichome fibers will be lost through the wastestream 114. The remaining portion of refined feedstock 110 is routed toa second air classifier 120 wherein outlet 122 primarily communicatestrichome fiber fines to a first collection device and outlet 124primarily communicates trichome fibers that are larger than the fines toa second collection device.

Processes that include a step of disassociating separated trichomefibers from leaves and stems can produce trichome fiber yields higherthan previously known processes, such as that exemplified in FIGS. 1 and2. The trichome fiber yields from processes of the present invention canbe greater than 15%, 20%, 25%, 30%, 33%, 35%, 37%, and more.

As noted above in relation to FIG. 3, outlet 122 of air classifier 120allows for the collection of trichome fiber fines, which include fibershaving a length of less than 100 microns. Trichome fiber fines canimpart a great deal of softness to a fibrous structure, wherein evensmall incorporation levels (e.g., 1%, 2%, 3%, 5%, 7.5%) of the fines canbe consumer noticeable in a final fibrous structure comprising productlike a sanitary tissue product.

Fiber collections from a prior art process (FIGS. 1 and 2) and a processaccording to the present invention (FIGS. 1 and 3) were analyzed with anL&W STFI Fibermaster instrument. Among other things, the instrumentreports length weighted proportion of fibers in various length ranges(e.g., 200-500 microns, 500-1500 microns, 1500-3000 microns), and alevel of fines reported as a percentage on a length weighted basis offibers having a length below 200 microns. Fiber collections from theprior art process contained 32% and 33% of fibers in the 200-500 micronrange, while the improved process of the present invention resulted infiber collections having 42% and 46% of its fibers in the 200-500 micronrange. And fiber collections from the prior art process contained 10.70%and 11.80% fines, while the improved process of the present inventionhad about twice the amount of fines (19.05% and 22.75%). Thus, theimproved processes enable collection of a higher percentage of smalltrichome fibers, which can impart various benefits to fibrous structurescomprising the same including, for example, better softness and betterflushability.

The inventors discovered that processes that include a step ofdisassociating separated trichome fibers from leaves and stems alsoproduce a cleaner mass of collected fibers (including speck-freetrichome fiber masses). As a result trichome fiber collections viaoutlet 122 and/or 124 can have L* color values of greater than or equalto about 70% and/or b* color values of less than or equal to about 15%.The color and intensity of the collected trichome fibers can be measuredby reflectance spectrophotometer ASTM standard test methodology.Tristimulus L*, a*, b* color values are reported in term of the CIE 1976color coordinate standard. Processes of the present invention, includingthat shown in FIG. 3 and similar process thereto, can eliminate the needfor a washing step prior to incorporating the collected trichome fibersinto a fibrous structure. One of ordinary skill in the art shouldappreciate however that an optional washing step can be used with theinventive processes to drive L* and/or b* values even higher. Forexample, an optional washing step can lead to trichome fiber masseshaving an L* color value of greater than or equal to about 80%, and/or ab* color value of less than or equal to about 10%. In others, the methodof the present invention may further comprise the step of washing theend mass of material (trichome fiber masses) to increase its L* and/orb* values. Fibrous structures and sanitary tissue products comprisingthe same can have L* values as high as 92% and 95%.

Feedstock 100 can come from a variety of sources. Essentially all plantshave trichomes. Those skilled in the art will recognize that some plantswill have trichomes of sufficient mass fraction and/or the overallgrowth rate and/or robustness of the plant so that they may offerattractive agricultural economy to make them more suitable for a largecommercial process, such as using them as a source of chemicals, e.g.cellulose, or assembling them into fibrous structures, such asdisposable fibrous structures. Trichomes may have a wide range ofmorphology and chemical properties. For example, the trichomes may be inthe form of fibers; namely, trichome fibers. Such trichome fibers mayhave a high length to diameter ratio.

The following sources are offered as non-limiting examples oftrichome-bearing plants (suitable sources) for obtaining trichomes,especially trichome fibers.

Non-limiting examples of suitable sources for obtaining trichomes,especially trichome fibers, are plants in the labiatae (Lamiaceae)family commonly referred to as the mint family.

Examples of suitable species in the labiatae family include Stachysbyzantina, also known as Stachys lanata commonly referred to as lamb'sear, woolly betony, or woundwort. The term Stachys byzantina as usedherein also includes cultivars Stachys byzantina ‘Primrose Heron’,Stachys byzantina ‘Helene von Stein’ (sometimes referred to as Stachysbyzantina ‘Big Ears’), Stachys byzantina ‘Cotton Boll’, Stachysbyzantina ‘Variegated’ (sometimes referred to as Stachys byzantina‘Striped Phantom’), and Stachys byzantina ‘Silver Carpet’.

Additional examples of suitable species in the labiatae family includethe arcticus subspecies of Thymus praecox, commonly referred to ascreeping thyme and the pseudolanuginosus subspecies of Thymus praecox,commonly referred to as wooly thyme.

Further examples of suitable species in the labiatae family includeseveral species in the genus Salvia (sage), including Salvia leucantha,commonly referred to as the Mexican bush sage; Salvia tarahumara,commonly referred to as the grape scented Indian sage; Salvia apiana,commonly referred to as white sage; Salvia funereal, commonly referredto as Death Valley sage; Salvia sagittata, commonly referred to asbalsamic sage; and Salvia argentiae, commonly referred to as silversage.

Even further examples of suitable species in the labiatae family includeLavandula lanata, commonly referred to as wooly lavender; Marrubiumvulgare, commonly referred to as horehound; Plectranthus argentatus,commonly referred to as silver shield; and Plectranthus tomentosa.

Non-limiting examples of other suitable sources for obtaining trichomes,especially trichome fibers are plants in the Asteraceae family commonlyreferred to as the sunflower family.

Examples of suitable species in the Asteraceae family include Artemisiastelleriana, also known as silver brocade; Haplopappus macronema, alsoknown as the whitestem goldenbush; Helichrysum petiolare; Centaureamaritime, also known as Centaurea gymnocarpa or dusty miller; Achilleatomentosum, also known as wooly yarrow; Anaphalis margaritacea, alsoknown as pearly everlasting; and Encelia farinose, also known as brittlebush.

Additional examples of suitable species in the Asteraceae family includeSenecio brachyglottis and Senecio haworthii, the latter also known asKleinia haworthii.

Non-limiting examples of other suitable sources for obtaining trichomes,especially trichome fibers, are plants in the Scrophulariaceae familycommonly referred to as the figwort or snapdragon family.

An example of a suitable species in the Scrophulariaceae family includesPedicularis kanei, also known as the wooly lousewort.

Additional examples of suitable species in the Scrophulariaceae familyinclude the mullein species (Verbascum) such as Verbascum hybridium,also known as snow maiden; Verbascum thapsus, also known as commonmullein; Verbascum baldaccii; Verbascum bombyciferum; Verbascum broussa;Verbascum chaixii; Verbascum dumulsum; Verbascum laciniatum; Verbascumlanatum; Verbascum longifolium; Verbascum lychnitis; Verbascumolympicum; Verbascum paniculatum; Verbascum phlomoides; Verbascumphoeniceum; Verbascum speciosum; Verbascum thapsiforme; Verbascumvirgatum; Verbascum wiedemannianum; and various mullein hybridsincluding Verbascum ‘Helen Johnson’ and Verbascum ‘Jackie’.

Further examples of suitable species in the Scrophulariaceae familyinclude Stemodia tomentosa and Stemodia durantifolia.

Non-limiting examples of other suitable sources for obtaining trichomes,especially trichome fibers include Greyia radlkoferi and Greyiaflanmaganii plants in the Greyiaceae family commonly referred to as thewild bottlebrush family.

Non-limiting examples of other suitable sources for obtaining trichomes,especially trichome fibers include members of the Fabaceae (legume)family. These include the Glycine max, commonly referred to as thesoybean, and Trifolium pratense L, commonly referred to as medium and/ormammoth red clover.

Non-limiting examples of other suitable sources for obtaining trichomes,especially trichome fibers include members of the Solanaceae familyincluding varieties of Lycopersicum esculentum, otherwise known as thecommon tomato.

Non-limiting examples of other suitable sources for obtaining trichomes,especially trichome fibers include members of the Convolvulaceae(morning glory) family, including Argyreia nervosa, commonly referred toas the wooly morning glory and Convolvulus cneorum, commonly referred toas the bush morning glory.

Non-limiting examples of other suitable sources for obtaining trichomes,especially trichome fibers include members of the Malvaceae (mallow)family, including Anoda cristata, commonly referred to as spurred anodaand Abutilon theophrasti, commonly referred to as velvetleaf.

Non-limiting examples of other suitable sources for obtaining trichomes,especially trichome fibers include Buddleia marrubiifolia, commonlyreferred to as the wooly butterfly bush of the Loganiaceae family; theCasimiroa tetrameria, commonly referred to as the wooly leafed sapote ofthe Rutaceae family; the Ceanothus tomentosus, commonly referred to asthe wooly leafed mountain liliac of the Rhamnaceae family; the ‘PhilippeVapelle’ cultivar of renardii in the Geraniaceae (geranium) family; theTibouchina urvilleana, commonly referred to as the Brazilian spiderflower of the Melastomataceae family; the Tillandsia recurvata, commonlyreferred to as ballmoss of the Bromeliaceae (pineapple) family; theHypericum tomentosum, commonly referred to as the wooly St. John's wortof the Hypericaceae family; the Chorizanthe orcuttiana, commonlyreferred to as the San Diego spineflower of the Polygonaceae family;Eremocarpus setigerus, commonly referred to as the doveweed of theEuphorbiaceae or spurge family; Kalanchoe tomentosa, commonly referredto as the panda plant of the Crassulaceae family; and Cynodon dactylon,commonly referred to as Bermuda grass, of the Poaceae family; and Congeatomentosa, commonly referred to as the shower orchid, of the Verbenaceaefamily.

Suitable trichome-bearing plants are commercially available fromnurseries and other plant-selling commercial venues. For example,Stachys byzantina may be purchased and/or viewed at Blanchette Gardens,Carlisle, Mass. In one example, a trichome fiber suitable for use in thefibrous structures of the present invention comprises cellulose. Inanother example, a trichome fiber suitable for use in the fibrousstructures of the present invention comprises a fatty acid. In anotherexample, a trichome fiber suitable for use in the fibrous structures ofthe present invention is hydrophobic. In yet another example, a trichomefiber suitable for use in the fibrous structures of the presentinvention is less hydrophilic that softwood fibers. This characteristicof the trichome fiber may facilitate a reduction in drying temperaturesneeded to dry fibrous structures comprising such trichome fiber and/ormay facilitate making the fibrous structures containing such trichomefiber at a faster rate.

As shown in FIG. 4, numerous trichomes 10 are present on this red cloverleaf and leaf stem. FIG. 5 shows numerous trichomes 10 present on a redclover lower stem.

As shown in FIG. 6, a dusty miller leaf is contains numerous trichomes10. FIG. 7 shows individualized trichomes 10′ obtained from a dustymiller leaf.

As shown in FIG. 8, a basal leaf on a silver sage contains numeroustrichomes 10. FIG. 9 shows trichomes 10 present on a bloom-stalk leaf ofa silver sage.

As shown in FIG. 10, trichomes 10 are present on a mature leaf of commonmullein. FIG. 11 shows trichomes 10 present on a juvenile leaf of commonmullein.

FIG. 12 shows, via a perpendicular view, trichomes 10 present on a leafof wooly betony. FIG. 13 is a cross-sectional view of a leaf of woolybetony containing trichomes 10. FIG. 14 shows individualized trichomes10′ obtained from a wooly betony leaf.

Trichome fibers can be liberated through processes of the presentinvention for incorporation into fibrous structures. “Fibrous structure”as used herein means a structure that comprises one or more fibers.Non-limiting examples of processes for making fibrous structures includeknown wet-laid papermaking processes and air-laid papermaking processes.Such processes typically include steps of preparing a fiber compositionin the form of a suspension in a medium, either wet, more specificallyaqueous medium, or dry, more specifically gaseous, i.e. with air asmedium. The aqueous medium used for wet-laid processes is oftentimesreferred to as a fiber slurry. The fibrous suspension is then used todeposit a plurality of fibers onto a forming wire or belt such that anembryonic fibrous structure is formed, after which drying and/or bondingthe fibers together results in a fibrous structure. Further processingthe fibrous structure may be carried out such that a finished fibrousstructure is formed. For example, in typical papermaking processes, thefinished fibrous structure is the fibrous structure that is wound on thereel at the end of papermaking, and may subsequently be converted into afinished product, e.g. a sanitary tissue product.

The fibrous structures will generally comprise a fiber blend. The fiberblend may comprise trichome fibers, for example trichome fibers thatexhibit a length of less than 100 microns, softwood fibers, and/orhardwood fibers. In one example, the fiber blend comprises at least 1%and/or at least 3% and/or at least 5% and/or at least 7.5% of trichomefibers. In one example, the fiber blend comprises at least 1% oftrichome fibers, and the wood fibers comprise both hardwood fibers andsoftwood fibers. Fibrous structures according to this invention maycontain from about 0.1% to about 100% and/or from about 0.5% to about90% and/or from about 0.5% to about 80% and/or from about 0.5% to about50% and/or from about 1% to about 40% and/or from about 2% to about 30%and/or from about 5% to about 25% by weight on a dry fiber basis oftrichome fibers.

The fiber blend may also include other fibers besides trichome fibers.Natural fibrous structure-making fibers useful in the present inventioninclude animal fibers, mineral fibers, other plant fibers (in additionto the trichomes of the present invention) and mixtures thereof. Animalfibers may, for example, be selected from the group consisting of: wool,silk and mixtures thereof. The other plant fibers may, for example, bederived from a plant selected from the group consisting of: wood,cotton, cotton linters, flax, sisal, abaca, hemp, hesperaloe, jute,bamboo, bagasse, kudzu, corn, sorghum, gourd, agave, loofah and mixturesthereof.

Wood fibers; often referred to as wood pulps include chemical pulps,such as kraft (sulfate) and sulfite pulps, as well as mechanical andsemi-chemical pulps including, for example, groundwood, thermomechanicalpulp, chemi-mechanical pulp (CMP), chemi-thermomechanical pulp (CTMP),neutral semi-chemical sulfite pulp (NSCS). Chemical pulps, however, maybe preferred since they impart a superior tactile sense of softness totissue sheets made therefrom. Pulps derived from both deciduous trees(hereinafter, also referred to as “hardwood”) and coniferous trees(hereinafter, also referred to as “softwood”) may be utilized. Thehardwood and softwood fibers can be blended, or alternatively, can bedeposited in layers to provide a stratified and/or layered web. U.S.Pat. Nos. 4,300,981 and 3,994,771 are incorporated herein by referencefor the purpose of disclosing layering of hardwood and softwood fibers.Also applicable to the present invention are fibers derived fromrecycled paper, which may contain any or all of the above categories aswell as other non-fibrous materials such as fillers and adhesives usedto facilitate the original papermaking.

The wood pulp fibers may be short (typical of hardwood fibers) or long(typical of softwood fibers). Non-limiting examples of short fibersinclude fibers derived from a fiber source selected from the groupconsisting of Acacia, Eucalyptus, Maple, Oak, Aspen, Birch, Cottonwood,Alder, Ash, Cherry, Elm, Hickory, Poplar, Gum, Walnut, Locust, Sycamore,Beech, Catalpa, Sassafras, Gmelina, Albizia, Anthocephalus, andMagnolia. Non-limiting examples of long fibers include fibers derivedfrom Pine, Spruce, Fir, Tamarack, Hemlock, Cypress, and Cedar. Softwoodfibers derived from the kraft process and originating from more-northernclimates may be preferred. These are often referred to as northernsoftwood kraft (NSK) pulps.

Synthetic fibers may be selected from the group consisting of: wet spunfibers, dry spun fibers, melt spun (including melt blown) fibers,synthetic pulp fibers and mixtures thereof. Synthetic fibers may, forexample, be comprised of cellulose (often referred to as “rayon”);cellulose derivatives such as esters, ether, or nitrous derivatives;polyolefins (including polyethylene and polypropylene); polyesters(including polyethylene terephthalate); polyamides (often referred to as“nylon”); acrylics; non-cellulosic polymeric carbohydrates (such asstarch, chitin and chitin derivatives such as chitosan); polylacticacids, polyhydroxyalkanoates, polycaprolactones, and mixtures thereof.In one example, synthetic fibers may be used as binding agent.

The fibrous structure may comprise fibers, films and/or foams thatcomprise a hydroxyl polymer and optionally a crosslinking system.Non-limiting examples of suitable hydroxyl polymers include polyols,such as polyvinyl alcohol, polyvinyl alcohol derivatives, polyvinylalcohol copolymers, starch, starch derivatives, chitosan, chitosanderivatives, cellulose derivatives such as cellulose ether and esterderivatives, gums, arabinans, galactans, proteins and various otherpolysaccharides and mixtures thereof. For example, a web of the fibrousstructure may comprise a continuous or substantially continuous fibercomprising a starch hydroxyl polymer and a polyvinyl alcohol hydroxylpolymer produced by dry spinning and/or solvent spinning (both unlikewet spinning into a coagulating bath) a composition comprising thestarch hydroxyl polymer and the polyvinyl alcohol hydroxyl polymer.

The fibrous structure may comprise other additives, such as wet strengthadditives, softening additives, solid additives (such as starch, clays),dry strength resins, wetting agents, lint resisting and/or reducingagents, absorbency-enhancing agents, immobilizing agents, especially incombination with emollient lotion compositions, antiviral agentsincluding organic acids, antibacterial agents, polyol polyesters,antimigration agents, polyhydroxy plasticizers and mixtures thereof.Such other additives may be added to the fiber furnish, the embryonicfibrous web and/or the fibrous structure. Such other additives may bepresent in the fibrous structure at any level based on the dry weight ofthe fibrous structure. The other additives may be present in the fibrousstructure at a level of from about 0.001 to about 50% and/or from about0.001 to about 20% and/or from about 0.01 to about 5% and/or from about0.03 to about 3% and/or from about 0.1 to about 1.0% by weight, on a dryfibrous structure basis.

Non-limiting types of fibrous structures include conventionallyfelt-pressed fibrous structures; pattern densified fibrous structures;and high-bulk, uncompacted fibrous structures. The fibrous structuresmay be of a homogenous or multilayered (two or three or more layers)construction; and the sanitary tissue products made therefrom may be ofa single-ply or multi-ply construction.

In one example, the fibrous structure is a pattern densified fibrousstructure characterized by having a relatively high-bulk region ofrelatively low fiber density and an array of densified regions ofrelatively high fiber density. The high-bulk field is characterized as afield of pillow regions. The densified zones are referred to as knuckleregions. The knuckle regions exhibit greater density than the pillowregions. The densified zones may be discretely spaced within thehigh-bulk field or may be interconnected, either fully or partially,within the high-bulk field. Typically, from about 8% to about 65% of thefibrous structure surface comprises densified knuckles, the knuckles mayexhibit a relative density of at least 125% of the density of thehigh-bulk field. Processes for making pattern densified fibrousstructures are well known in the art as exemplified in U.S. Pat. Nos.3,301,746, 3,974,025, 4,191,609 and 4,637,859.

The fibrous structures comprising a trichome fiber in accordance withthe present invention may be in the form of through-air-dried fibrousstructures, differential density fibrous structures, differential basisweight fibrous structures, wet laid fibrous structures, air laid fibrousstructures (examples of which are described in U.S. Pat. Nos. 3,949,035and 3,825,381), conventional dried fibrous structures, creped oruncreped fibrous structures, patterned-densified ornon-patterned-densified fibrous structures, compacted or uncompactedfibrous structures, nonwoven fibrous structures comprising synthetic ormulticomponent fibers, homogeneous or multilayered fibrous structures,double re-creped fibrous structures, foreshortened fibrous structures,co-form fibrous structures (examples of which are described in U.S. Pat.No. 4,100,324) and mixtures thereof.

In one example, the air laid fibrous structure is selected from thegroup consisting of thermal bonded air laid (TBAL) fibrous structures,latex bonded air laid (LBAL) fibrous structures and mixed bonded airlaid (MBAL) fibrous structures.

The fibrous structures may exhibit a substantially uniform density ormay exhibit differential density regions, in other words regions of highdensity compared to other regions within the patterned fibrousstructure. Typically, when a fibrous structure is not pressed against acylindrical dryer, such as a Yankee dryer, while the fibrous structureis still wet and supported by a through-air-drying fabric or by anotherfabric or when an air laid fibrous structure is not spot bonded, thefibrous structure typically exhibits a substantially uniform density.

The fibrous structures of the present invention may be subjected to anysuitable post processing including, but not limited to, printing,embossing, calendaring, slitting, folding, combining with other fibrousstructures, and the like.

The fibrous structures of the present invention are particularly usefulfor making sanitary tissue products. “Sanitary tissue product” as usedherein means a soft, low density (i.e. <about 0.15 g/cm³) web useful asa wiping implement for post-urinary and post-bowel movement cleaning(toilet tissue), for otorhinolaryngological discharges (facial tissue),and multi-functional absorbent and cleaning uses (absorbent towels). Thesanitary tissue product may be convolutedly wound upon itself about acore or without a core to form a sanitary tissue product roll. Thesanitary tissue products may exhibit a basis weight between about 10g/m² to about 120 g/m² and/or from about 15 g/m² to about 110 g/m²and/or from about 20 g/m² to about 100 g/m² and/or from about 30 to 90g/m². In addition, the sanitary tissue product may exhibit a basisweight between about 40 g/m² to about 120 g/m² and/or from about 50 g/m²to about 110 g/m² and/or from about 55 g/m² to about 105 g/m² and/orfrom about 60 to 100 g/m² as measured according to the Basis Weight TestMethod described herein.

The sanitary tissue products may exhibit a total dry tensile of at least150 g/in and/or from about 200 g/in to about 1000 g/in and/or from about250 g/in to about 850 g/in as measured according to the Total DryTensile Test Method described herein.

In another example, the sanitary tissue product may exhibit a total drytensile of at least 300 g/in and/or at least 350 g/in and/or at least400 g/in and/or at least 450 g/in and/or at least 500 g/in and/or fromabout 500 g/in to about 1000 g/in and/or from about 550 g/in to about850 g/in and/or from about 600 g/in to about 800 g/in as measuredaccording to the Total Dry Tensile Test Method described herein. In oneexample, the sanitary tissue product exhibits a total dry tensilestrength of less than 1000 g/in and/or less than 850 g/in as measuredaccording to the Total Dry Tensile Test Method described herein.

In another example, the sanitary tissue product may exhibit a total drytensile of at least 500 g/in and/or at least 600 g/in and/or at least700 g/in and/or at least 800 g/in and/or at least 900 g/in and/or atleast 1000 g/in and/or from about 800 g/in to about 5000 g/in and/orfrom about 900 g/in to about 3000 g/in and/or from about 900 g/in toabout 2500 g/in and/or from about 1000 g/in to about 2000 g/in asmeasured according to the Total Dry Tensile Test Method describedherein.

“Basis Weight” as used herein is the weight per unit area of a samplereported in lbs./3000 ft² or g/m². Basis weight is measured by preparingone or more samples of a certain area (m²) and weighing the sample(s) ofa fibrous structure according to the present invention and/or a sanitarytissue product comprising such fibrous structure on a top loadingbalance with a minimum resolution of 0.01 g. The balance is protectedfrom air drafts and other disturbances using a draft shield. Weights arerecorded when the readings on the balance become constant. The averageweight (g) is calculated and the average area of the samples (m²) ismeasured. The basis weight (g/m²) is calculated by dividing the averageweight (g) by the average area of the samples (m²).

“Softness” of a fibrous structure according to the present inventionand/or a paper product comprising such fibrous structure is determinedas follows. Ideally, prior to softness testing, the samples to be testedshould be conditioned according to Tappi Method #T4020M-88. Here,samples are preconditioned for 24 hours at a relative humidity level of10 to 35% and within a temperature range of 22° C. to 40° C. After thispreconditioning step, samples should be conditioned for 24 hours at arelative humidity of 48% to 52% and within a temperature range of 22° C.to 24° C. Ideally, the softness panel testing should take place withinthe confines of a constant temperature and humidity room. If this is notfeasible, all samples, including the controls, should experienceidentical environmental exposure conditions.

Softness testing is performed as a paired comparison in a form similarto that described in “Manual on Sensory Testing Methods”, ASTM SpecialTechnical Publication 434, published by the American Society For Testingand Materials 1968 and is incorporated herein by reference. Softness isevaluated by subjective testing using what is referred to as a PairedDifference Test. The method employs a standard external to the testmaterial itself. For tactile perceived softness two samples arepresented such that the subject cannot see the samples, and the subjectis required to choose one of them on the basis of tactile softness. Theresult of the test is reported in what is referred to as Panel ScoreUnit (PSU). With respect to softness testing to obtain the softness datareported herein in PSU, a number of softness panel tests are performed.In each test ten practiced softness judges are asked to rate therelative softness of three sets of paired samples. The pairs of samplesare judged one pair at a time by each judge: one sample of each pairbeing designated X and the other Y. Briefly, each X sample is gradedagainst its paired Y sample as follows:

1. a grade of plus one is given if X is judged to may be a little softerthan Y, and a grade of minus one is given if Y is judged to may be alittle softer than X;

2. a grade of plus two is given if X is judged to surely be a littlesofter than Y, and a grade of minus two is given if Y is judged tosurely be a little softer than X;

3. a grade of plus three is given to X if it is judged to be a lotsofter than Y, and a grade of minus three is given if Y is judged to bea lot softer than X; and, lastly:

4. a grade of plus four is given to X if it is judged to be a whole lotsofter than Y, and a grade of minus 4 is given if Y is judged to be awhole lot softer than X.

The grades are averaged and the resultant value is in units of PSU. Theresulting data are considered the results of one panel test. If morethan one sample pair is evaluated then all sample pairs are rank orderedaccording to their grades by paired statistical analysis. Then, the rankis shifted up or down in value as required to give a zero PSU value towhich ever sample is chosen to be the zero-base standard. The othersamples then have plus or minus values as determined by their relativegrades with respect to the zero base standard. The number of panel testsperformed and averaged is such that about 0.2 PSU represents asignificant difference in subjectively perceived softness.

Any suitable process for making fibrous structures known in the art maybe used to make trichome-containing fibrous structures of the presentinvention. In one example, the trichome-containing fibrous structures ofthe present invention are made by a wet laid fibrous structure makingprocess. In another example, the trichome-containing fibrous structuresof the present invention are made by an air laid fibrous structuremaking process. In one example, a trichome-containing fibrous structureis made by the process comprising the steps of: a) preparing a fiberfurnish (slurry) by mixing a trichome with water; b) depositing thefiber furnish on a foraminous forming surface to form an embryonicfibrous web; and c) drying the embryonic fibrous web. In one example, afiber furnish comprising a trichome, such as a trichome fiber, isdeposited onto a foraminuous forming surface via a headbox.

The following Example illustrates a non-limiting example for thepreparation of sanitary tissue product comprising a fibrous structureaccording to the present invention on a pilot-scale Fourdrinier fibrousstructure making machine. Individualized trichomes can be first preparedfrom Stachys byzantina bloom stalks consisting of the dried stems,leaves, and pre-flowering buds, by processing dried Stachys byzantinaplant matter through steps as shown in FIGS. 1 and 3 above.

Special care must be taken while processing the trichomes. Sixty poundsof trichome fiber is pulped in a 50 gallon pulper by adding water inhalf amount required to make a 1% trichome fiber slurry. This is done toprevent trichome fibers over flowing and floating on surface of thewater due to lower density and hydrophobic nature of the trichome fiber.After mixing and stirring a few minutes, the pulper is stopped and theremaining trichome fibers are pushed in while water is added. After pHadjustment, it is pulped for 30 minutes, then dumped in a separate chestfor delivery onto the machine headbox. This allows one to place trichomefibers in one or more layers, alone or mixed with other fibers, such ashardwood fibers and/or softwood fibers. During this particular run, thetrichome fibers are added exclusively on the wire outer layer as theproduct is converted wire side up; therefore it is desirable to add thetrichome fibers to the wire side (the side where the tactile feel sensespaper the most).

The aqueous slurry of eucalyptus fibers is prepared at about 3% byweight using a conventional repulper. This slurry is also passed througha stock pipe toward the stock pipe containing the trichome fiber slurry.

The 1% trichome fiber slurry is combined with the 3% eucalyptus fiberslurry in a proportion which yields about 13.3% trichome fibers and86.7% eucalyptus fibers. The stockpipe containing the combined trichomeand eucalyptus fiber slurries is directed toward the wire layer ofheadbox of a Fourdrinier machine.

In order to impart temporary wet strength to the finished fibrousstructure, a 1% dispersion of temporary wet strengthening additive(e.g., Fennorez 91® commercially available from Kemira) is prepared andis added to the NSK fiber stock pipe at a rate sufficient to deliver0.3% temporary wet strengthening additive based on the dry weight of theNSK fibers. The absorption of the temporary wet strengthening additiveis enhanced by passing the treated slurry through an in-line mixer.

The trichome fiber and eucalyptus fiber slurry is diluted with whitewater at the inlet of a fan pump to a consistency of about 0.15% basedon the total weight of the eucalyptus and trichome fiber slurry. The NSKfibers, likewise, are diluted with white water at the inlet of a fanpump to a consistency of about 0.15% based on the total weight of theNSK fiber slurry. The eucalyptus/trichome fiber slurry and the NSK fiberslurry are both directed to a layered headbox capable of maintaining theslurries as separate streams until they are deposited onto a formingfabric on the Fourdrinier.

“DC 2310” antifoam is dripped into the wirepit to control foam tomaintain whitewater levels of 10 ppm of antifoam.

The fibrous structure making machine has a layered headbox having a topchamber, a center chamber, and a bottom chamber. The eucalyptus/trichomecombined fiber slurry is pumped through the top headbox chamber,eucalyptus fiber slurry is pumped through the bottom headbox chamber,and, simultaneously, the NSK fiber slurry is pumped through the centerheadbox chamber and delivered in superposed relation onto theFourdrinier wire to form thereon a three-layer embryonic web, of whichabout 83% is made up of the eucalyptus/trichome fibers and 17% is madeup of the NSK fibers. Dewatering occurs through the Fourdrinier wire andis assisted by a deflector and vacuum boxes. The Fourdrinier wire is ofa 5-shed, satin weave configuration having 87 machine-direction and 76cross-machine-direction monofilaments per inch, respectively. The speedof the Fourdrinier wire is about 750 fpm (feet per minute).

The embryonic wet web is transferred from the Fourdrinier wire, at afiber consistency of about 15% at the point of transfer, to a patterneddrying fabric. The speed of the patterned drying fabric is the same asthe speed of the Fourdrinier wire. The drying fabric is designed toyield a pattern densified tissue with discontinuous low-densitydeflected areas arranged within a continuous network of high density(knuckle) areas. This drying fabric is formed by casting an imperviousresin surface onto a fiber mesh supporting fabric. The supporting fabricis a 45×52 filament, dual layer mesh. The thickness of the resin cast isabout 12 mils above the supporting fabric. A suitable process for makingthe patterned drying fabric is described in published application US2004/0084167 A1.

Further de-watering is accomplished by vacuum assisted drainage untilthe web has a fiber consistency of about 30%.

While remaining in contact with the patterned drying fabric, the web ispre-dried by air blow-through pre-dryers to a fiber consistency of about65% by weight.

After the pre-dryers, the semi-dry web is transferred to the Yankeedryer and adhered to the surface of the Yankee dryer with a sprayedcreping adhesive. The creping adhesive is an aqueous dispersion with theactives consisting of about 22% polyvinyl alcohol, about 11% CREPETROLA3025, and about 67% CREPETROL R6390. CREPETROL A3025 and CREPETROLR6390 are commercially available from Hercules Incorporated ofWilmington, Del. The creping adhesive is delivered to the Yankee surfaceat a rate of about 0.15% adhesive solids based on the dry weight of theweb. The fiber consistency is increased to about 97% before the web isdry creped from the Yankee with a doctor blade.

The doctor blade has a bevel angle of about 25 degrees and is positionedwith respect to the Yankee dryer to provide an impact angle of about 81degrees. The Yankee dryer is operated at a temperature of about 350° F.(177° C.) and a speed of about 800 fpm. The fibrous structure is woundin a roll using a surface driven reel drum having a surface speed ofabout 656 feet per minute. The fibrous structure may be subsequentlyconverted into a two-ply sanitary tissue product having a basis weightof about 50 g/m².

Test Methods

Unless otherwise specified, all tests described herein including thosedescribed under the Definitions section and the following test methodsare conducted on samples that have been conditioned in a conditionedroom at a temperature of 73° F.±4° F. (about 23° C.±2.2° C.) and arelative humidity of 50%±10% for 2 hours prior to the test. All testsare conducted in such conditioned room. Do not test samples that havedefects such as wrinkles, tears, holes, and like.

Total Dry Tensile Strength Test Method

Cut at least eight 1 inch wide strips of the fibrous structure and/orsanitary tissue product to be tested in the machine direction. Cut atleast eight 1 inch wide strips in the cross direction. If the machinedirection and cross direction are not readily ascertainable, then thecross direction will be the strips that result in the lower peak loadtensile. For the wet measurements, each sample is wetted by submergingthe sample in a distilled water bath for 30 seconds. The wet property ofthe wet sample is measured within 30 seconds of removing the sample fromthe bath.

For the actual measurements of the properties, use a Thwing-AlbertIntelect II Standard Tensile Tester (Thwing-Albert Instrument Co. ofPhiladelphia, Pa.). Insert the flat face clamps into the unit andcalibrate the tester according to the instructions given in theoperation manual of the Thwing-Albert Intelect II. Set the instrumentcrosshead speed to 4.00 in/min and the 1st and 2nd gauge lengths to 4.00inches. The break sensitivity is set to 20.0 grams and the sample widthis set to 1.00 inch. The energy units are set to TEA and the tangentmodulus (Modulus) trap setting is set to 38.1 g.

After inserting the fibrous structure sample strip into the two clamps,the instrument tension can be monitored. If it shows a value of 5 gramsor more, the fibrous structure sample strip is too taut. Conversely, ifa period of 2-3 seconds passes after starting the test before any valueis recorded, the fibrous structure sample strip is too slack.

Start the tensile tester as described in the tensile tester instrumentmanual. When the test is complete, read and record the following withunits of measure:

Peak Load Tensile (Tensile Strength) (g/in)

Peak Elongation (Elongation) (%)

Peak CD TEA (Wet CD TEA) (in-g/in²)

Tangent Modulus (Dry MD Modulus and Dry CD Modulus) (at 15 g/cm)

Test each of the samples in the same manner, recording the abovemeasured values from each test. Average the values for each propertyobtained from the samples tested to obtain the reported value for thatproperty.

Total Dry Tensile (TDT)=Peak Load MD Tensile (g/in)+Peak Load CD Tensile(g/in)

The dimensions and values disclosed herein are not to be understood asbeing strictly limited to the exact numerical values recited. Instead,unless otherwise specified, each such dimension is intended to mean boththe recited value and a functionally equivalent range surrounding thatvalue. For example, a dimension disclosed as “40 mm” is intended to mean“about 40 mm.”

Every document cited herein, including any cross referenced or relatedpatent or application and any patent application or patent to which thisapplication claims priority or benefit thereof, is hereby incorporatedherein by reference in its entirety unless expressly excluded orotherwise limited. The citation of any document is not an admission thatit is prior art with respect to any invention disclosed or claimedherein or that it alone, or in any combination with any other referenceor references, teaches, suggests or discloses any such invention.Further, to the extent that any meaning or definition of a term in thisdocument conflicts with any meaning or definition of the same term in adocument incorporated by reference, the meaning or definition assignedto that term in this document shall govern.

While particular embodiments of the present invention have beenillustrated and described, it would be obvious to those skilled in theart that various other changes and modifications can be made withoutdeparting from the spirit and scope of the invention. It is thereforeintended to cover in the appended claims all such changes andmodifications that are within the scope of this invention.

What is claimed is:
 1. A fibrous structure comprising: a fiber blendthat comprises wood fibers and trichome fibers; wherein at least some ofthe trichome fibers have a length that is less than 100 microns; whereinthe fiber blend comprises from about 1% to about 40% of trichome fibers;wherein the wood fibers comprise both hardwood fibers and softwoodfibers; and wherein the trichome fibers comprise an L* color value ofgreater than about 70%.
 2. The fibrous structure of claim 1, wherein thetrichome fibers comprise a b* color value of less than about 15%.
 3. Thefibrous structure of claim 1, wherein the trichome fibers are derivedfrom a plant in the Stachys genus.
 4. The fibrous structure of claim 1,wherein the fiber blend comprises from about 2% to about 30% of trichomefibers.
 5. The fibrous structure of claim 1, wherein the fiber blendcomprises from about 5% to about 25% of trichome fibers.
 6. The fibrousstructure of claim 1, wherein the trichome fibers are derived from aplant in the Stachys genus.
 7. A single or multi ply sanitary tissueproduct comprising the fibrous structure according to claim
 1. 8. Thesanitary tissue product of claim 7, wherein the fibrous structurecomprises an additive selected from the group consisting of: wetstrength additives, softening agents, and mixtures thereof.
 9. Thesanitary tissue product of claim 7, wherein the sanitary tissue productexhibits a total dry tensile of from about 200 g/in to about 1000 g/in,as measured according to the Total Dry Tensile Test Method describedherein.
 10. The sanitary tissue product of claim 7, wherein the sanitarytissue product is toilet tissue.
 11. The fibrous structure of claim 1,wherein the trichome fibers are derived from a plant in the Stachysgenus.